Gulf storm can aid tsunami mitigation

A study of storm surge damage from Hurricane Katrina in Gulf Coast areas may lead to improved guidelines for construction to protect against tsunamis, says a University of Hawaii-Manoa engineer.

"Storm surge rises less rapidly than a tsunami, obviously, but deep water flowing through structures has a similar effect, particularly when transporting debris," Ian Robertson, associate professor of civil and environmental engineering, said in a telephone interview from Mississippi.

Robertson and Ron Riggs, professor and chairman of civil and environmental engineering, are leading a multi-university, four-year research project funded with $1.3 million from the National Science Foundation.

The NSF's National Earthquake Engineering Simulation-Research Program is seeking performance-based tsunami engineering guidelines for construction of buildings in coastal areas subject to tsunamis or hurricane storm surge.

Robertson said the Honolulu building code has provisions for tsunamis that "actually are some of the best available."

The engineers looked at guidelines around the country and Honolulu has the best at present, he said. "But a lot of it is based on research at least 20 years old," he added, noting most are based on a report published in 1980.

The project is intended to improve on those provisions and develop performance-based tsunami design criteria, he said.

Robertson and Riggs are in Mississippi to document effects of the hurricane storm surge on the infrastructure along an industrial coastline.

They are collecting data on the type and quantity of water-borne debris that may have impacted coastal buildings.

"Satellite images of the area indicate debris ranging from automobiles and power poles in residential areas to shipping containers and barges in industrial and port areas," Robertson said.

The UH-Manoa engineers also will record the effect of debris on engineered structures, such as multi-story buildings, in the coastal inundation zone.

In late October, co-investigators Solomon Yim of Oregon Sate University and Julie Young of Princeton will collect data on bridge and scour damage.

The UH engineers are partnering with the International Tsunami Information Center, Robertson said.